It lived in the Late Jurassic and Early Cretaceous of Europe and North Africa.

In the analysis performed by Panciroli and colleagues (2018), Peramus was recovered as within a clade also including Palaeoxonodon and Amphitherium, as derived members of Cladotheria.

Peramus, Palaeoxonodon and Amphitherium were united by the shared traits of "convergence of the Meckel’s sulcus with the ventral border of the mandible; and possessing open rooted postcanines."

[4] In a 2018 analysis by Bi and colleagues, Peramus was recovered in a clade with Palaeoxonodon and Nanolestes also as advanced cladotherians.

[5] In a 2022 study of cladotherian relationships, it was recovered as a member of Zatheria, closer to Theria than either Palaeoxonodon and Nanolestes.